Linux Audio

Check our new training course

Loading...
v5.9
  1// SPDX-License-Identifier: GPL-2.0
  2#include <linux/smp.h>
  3#include <linux/cpu.h>
 
 
 
 
 
 
 
 
 
 
 
 
 
  4#include <linux/slab.h>
  5#include <linux/cpumask.h>
  6#include <linux/percpu.h>
 
 
 
 
 
 
 
 
 
 
 
 
 
  7
 
 
  8#include <xen/events.h>
  9
 10#include <xen/hvc-console.h>
 11#include "xen-ops.h"
 
 12#include "smp.h"
 
 13
 
 
 
 
 
 
 14static DEFINE_PER_CPU(struct xen_common_irq, xen_resched_irq) = { .irq = -1 };
 15static DEFINE_PER_CPU(struct xen_common_irq, xen_callfunc_irq) = { .irq = -1 };
 16static DEFINE_PER_CPU(struct xen_common_irq, xen_callfuncsingle_irq) = { .irq = -1 };
 
 17static DEFINE_PER_CPU(struct xen_common_irq, xen_debug_irq) = { .irq = -1 };
 
 18
 19static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
 20static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
 
 21
 22/*
 23 * Reschedule call back.
 24 */
 25static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
 26{
 27	inc_irq_stat(irq_resched_count);
 28	scheduler_ipi();
 29
 30	return IRQ_HANDLED;
 31}
 32
 33void xen_smp_intr_free(unsigned int cpu)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 34{
 35	if (per_cpu(xen_resched_irq, cpu).irq >= 0) {
 36		unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu).irq, NULL);
 37		per_cpu(xen_resched_irq, cpu).irq = -1;
 38		kfree(per_cpu(xen_resched_irq, cpu).name);
 39		per_cpu(xen_resched_irq, cpu).name = NULL;
 40	}
 41	if (per_cpu(xen_callfunc_irq, cpu).irq >= 0) {
 42		unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu).irq, NULL);
 43		per_cpu(xen_callfunc_irq, cpu).irq = -1;
 44		kfree(per_cpu(xen_callfunc_irq, cpu).name);
 45		per_cpu(xen_callfunc_irq, cpu).name = NULL;
 46	}
 47	if (per_cpu(xen_debug_irq, cpu).irq >= 0) {
 48		unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu).irq, NULL);
 49		per_cpu(xen_debug_irq, cpu).irq = -1;
 50		kfree(per_cpu(xen_debug_irq, cpu).name);
 51		per_cpu(xen_debug_irq, cpu).name = NULL;
 52	}
 53	if (per_cpu(xen_callfuncsingle_irq, cpu).irq >= 0) {
 54		unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu).irq,
 55				       NULL);
 56		per_cpu(xen_callfuncsingle_irq, cpu).irq = -1;
 57		kfree(per_cpu(xen_callfuncsingle_irq, cpu).name);
 58		per_cpu(xen_callfuncsingle_irq, cpu).name = NULL;
 59	}
 60}
 
 
 
 
 
 
 
 
 61
 62int xen_smp_intr_init(unsigned int cpu)
 
 
 
 
 
 
 
 63{
 64	int rc;
 65	char *resched_name, *callfunc_name, *debug_name;
 66
 67	resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
 68	rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
 69				    cpu,
 70				    xen_reschedule_interrupt,
 71				    IRQF_PERCPU|IRQF_NOBALANCING,
 72				    resched_name,
 73				    NULL);
 74	if (rc < 0)
 75		goto fail;
 76	per_cpu(xen_resched_irq, cpu).irq = rc;
 77	per_cpu(xen_resched_irq, cpu).name = resched_name;
 78
 79	callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
 80	rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
 81				    cpu,
 82				    xen_call_function_interrupt,
 83				    IRQF_PERCPU|IRQF_NOBALANCING,
 84				    callfunc_name,
 85				    NULL);
 86	if (rc < 0)
 87		goto fail;
 88	per_cpu(xen_callfunc_irq, cpu).irq = rc;
 89	per_cpu(xen_callfunc_irq, cpu).name = callfunc_name;
 90
 91	debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
 92	rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt,
 93				     IRQF_PERCPU | IRQF_NOBALANCING,
 94				     debug_name, NULL);
 95	if (rc < 0)
 96		goto fail;
 97	per_cpu(xen_debug_irq, cpu).irq = rc;
 98	per_cpu(xen_debug_irq, cpu).name = debug_name;
 99
100	callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
101	rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
102				    cpu,
103				    xen_call_function_single_interrupt,
104				    IRQF_PERCPU|IRQF_NOBALANCING,
105				    callfunc_name,
106				    NULL);
107	if (rc < 0)
108		goto fail;
109	per_cpu(xen_callfuncsingle_irq, cpu).irq = rc;
110	per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name;
111
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
112	return 0;
113
114 fail:
115	xen_smp_intr_free(cpu);
116	return rc;
117}
118
119void __init xen_smp_cpus_done(unsigned int max_cpus)
120{
121	int cpu, rc, count = 0;
122
123	if (xen_hvm_domain())
124		native_smp_cpus_done(max_cpus);
125	else
126		calculate_max_logical_packages();
127
128	if (xen_have_vcpu_info_placement)
129		return;
130
131	for_each_online_cpu(cpu) {
132		if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS)
133			continue;
 
 
 
 
 
 
 
 
 
 
134
135		rc = remove_cpu(cpu);
 
136
137		if (rc == 0) {
138			/*
139			 * Reset vcpu_info so this cpu cannot be onlined again.
140			 */
141			xen_vcpu_info_reset(cpu);
142			count++;
 
143		} else {
144			pr_warn("%s: failed to bring CPU %d down, error %d\n",
145				__func__, cpu, rc);
 
146		}
147	}
148	WARN(count, "%s: brought %d CPUs offline\n", __func__, count);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
149}
150
151void xen_smp_send_reschedule(int cpu)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
152{
153	xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
154}
155
156static void __xen_send_IPI_mask(const struct cpumask *mask,
157			      int vector)
158{
159	unsigned cpu;
160
161	for_each_cpu_and(cpu, mask, cpu_online_mask)
162		xen_send_IPI_one(cpu, vector);
163}
164
165void xen_smp_send_call_function_ipi(const struct cpumask *mask)
166{
167	int cpu;
168
169	__xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
170
171	/* Make sure other vcpus get a chance to run if they need to. */
172	for_each_cpu(cpu, mask) {
173		if (xen_vcpu_stolen(cpu)) {
174			HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
175			break;
176		}
177	}
178}
179
180void xen_smp_send_call_function_single_ipi(int cpu)
181{
182	__xen_send_IPI_mask(cpumask_of(cpu),
183			  XEN_CALL_FUNCTION_SINGLE_VECTOR);
184}
185
186static inline int xen_map_vector(int vector)
187{
188	int xen_vector;
189
190	switch (vector) {
191	case RESCHEDULE_VECTOR:
192		xen_vector = XEN_RESCHEDULE_VECTOR;
193		break;
194	case CALL_FUNCTION_VECTOR:
195		xen_vector = XEN_CALL_FUNCTION_VECTOR;
196		break;
197	case CALL_FUNCTION_SINGLE_VECTOR:
198		xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
199		break;
200	case IRQ_WORK_VECTOR:
201		xen_vector = XEN_IRQ_WORK_VECTOR;
202		break;
203#ifdef CONFIG_X86_64
204	case NMI_VECTOR:
205	case APIC_DM_NMI: /* Some use that instead of NMI_VECTOR */
206		xen_vector = XEN_NMI_VECTOR;
207		break;
208#endif
209	default:
210		xen_vector = -1;
211		printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
212			vector);
213	}
214
215	return xen_vector;
216}
217
218void xen_send_IPI_mask(const struct cpumask *mask,
219			      int vector)
220{
221	int xen_vector = xen_map_vector(vector);
222
223	if (xen_vector >= 0)
224		__xen_send_IPI_mask(mask, xen_vector);
225}
226
227void xen_send_IPI_all(int vector)
228{
229	int xen_vector = xen_map_vector(vector);
230
231	if (xen_vector >= 0)
232		__xen_send_IPI_mask(cpu_online_mask, xen_vector);
233}
234
235void xen_send_IPI_self(int vector)
236{
237	int xen_vector = xen_map_vector(vector);
238
239	if (xen_vector >= 0)
240		xen_send_IPI_one(smp_processor_id(), xen_vector);
241}
242
243void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
244				int vector)
245{
246	unsigned cpu;
247	unsigned int this_cpu = smp_processor_id();
248	int xen_vector = xen_map_vector(vector);
249
250	if (!(num_online_cpus() > 1) || (xen_vector < 0))
251		return;
252
253	for_each_cpu_and(cpu, mask, cpu_online_mask) {
254		if (this_cpu == cpu)
255			continue;
256
257		xen_send_IPI_one(cpu, xen_vector);
258	}
259}
260
261void xen_send_IPI_allbutself(int vector)
262{
263	xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
264}
265
266static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
267{
268	irq_enter();
269	generic_smp_call_function_interrupt();
270	inc_irq_stat(irq_call_count);
271	irq_exit();
272
273	return IRQ_HANDLED;
274}
275
276static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
277{
278	irq_enter();
279	generic_smp_call_function_single_interrupt();
280	inc_irq_stat(irq_call_count);
281	irq_exit();
282
283	return IRQ_HANDLED;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
284}
v4.6
  1/*
  2 * Xen SMP support
  3 *
  4 * This file implements the Xen versions of smp_ops.  SMP under Xen is
  5 * very straightforward.  Bringing a CPU up is simply a matter of
  6 * loading its initial context and setting it running.
  7 *
  8 * IPIs are handled through the Xen event mechanism.
  9 *
 10 * Because virtual CPUs can be scheduled onto any real CPU, there's no
 11 * useful topology information for the kernel to make use of.  As a
 12 * result, all CPUs are treated as if they're single-core and
 13 * single-threaded.
 14 */
 15#include <linux/sched.h>
 16#include <linux/err.h>
 17#include <linux/slab.h>
 18#include <linux/smp.h>
 19#include <linux/irq_work.h>
 20#include <linux/tick.h>
 21
 22#include <asm/paravirt.h>
 23#include <asm/desc.h>
 24#include <asm/pgtable.h>
 25#include <asm/cpu.h>
 26
 27#include <xen/interface/xen.h>
 28#include <xen/interface/vcpu.h>
 29#include <xen/interface/xenpmu.h>
 30
 31#include <asm/xen/interface.h>
 32#include <asm/xen/hypercall.h>
 33
 34#include <xen/xen.h>
 35#include <xen/page.h>
 36#include <xen/events.h>
 37
 38#include <xen/hvc-console.h>
 39#include "xen-ops.h"
 40#include "mmu.h"
 41#include "smp.h"
 42#include "pmu.h"
 43
 44cpumask_var_t xen_cpu_initialized_map;
 45
 46struct xen_common_irq {
 47	int irq;
 48	char *name;
 49};
 50static DEFINE_PER_CPU(struct xen_common_irq, xen_resched_irq) = { .irq = -1 };
 51static DEFINE_PER_CPU(struct xen_common_irq, xen_callfunc_irq) = { .irq = -1 };
 52static DEFINE_PER_CPU(struct xen_common_irq, xen_callfuncsingle_irq) = { .irq = -1 };
 53static DEFINE_PER_CPU(struct xen_common_irq, xen_irq_work) = { .irq = -1 };
 54static DEFINE_PER_CPU(struct xen_common_irq, xen_debug_irq) = { .irq = -1 };
 55static DEFINE_PER_CPU(struct xen_common_irq, xen_pmu_irq) = { .irq = -1 };
 56
 57static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
 58static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
 59static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id);
 60
 61/*
 62 * Reschedule call back.
 63 */
 64static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
 65{
 66	inc_irq_stat(irq_resched_count);
 67	scheduler_ipi();
 68
 69	return IRQ_HANDLED;
 70}
 71
 72static void cpu_bringup(void)
 73{
 74	int cpu;
 75
 76	cpu_init();
 77	touch_softlockup_watchdog();
 78	preempt_disable();
 79
 80	/* PVH runs in ring 0 and allows us to do native syscalls. Yay! */
 81	if (!xen_feature(XENFEAT_supervisor_mode_kernel)) {
 82		xen_enable_sysenter();
 83		xen_enable_syscall();
 84	}
 85	cpu = smp_processor_id();
 86	smp_store_cpu_info(cpu);
 87	cpu_data(cpu).x86_max_cores = 1;
 88	set_cpu_sibling_map(cpu);
 89
 90	xen_setup_cpu_clockevents();
 91
 92	notify_cpu_starting(cpu);
 93
 94	set_cpu_online(cpu, true);
 95
 96	cpu_set_state_online(cpu);  /* Implies full memory barrier. */
 97
 98	/* We can take interrupts now: we're officially "up". */
 99	local_irq_enable();
100}
101
102/*
103 * Note: cpu parameter is only relevant for PVH. The reason for passing it
104 * is we can't do smp_processor_id until the percpu segments are loaded, for
105 * which we need the cpu number! So we pass it in rdi as first parameter.
106 */
107asmlinkage __visible void cpu_bringup_and_idle(int cpu)
108{
109#ifdef CONFIG_XEN_PVH
110	if (xen_feature(XENFEAT_auto_translated_physmap) &&
111	    xen_feature(XENFEAT_supervisor_mode_kernel))
112		xen_pvh_secondary_vcpu_init(cpu);
113#endif
114	cpu_bringup();
115	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
116}
117
118static void xen_smp_intr_free(unsigned int cpu)
119{
120	if (per_cpu(xen_resched_irq, cpu).irq >= 0) {
121		unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu).irq, NULL);
122		per_cpu(xen_resched_irq, cpu).irq = -1;
123		kfree(per_cpu(xen_resched_irq, cpu).name);
124		per_cpu(xen_resched_irq, cpu).name = NULL;
125	}
126	if (per_cpu(xen_callfunc_irq, cpu).irq >= 0) {
127		unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu).irq, NULL);
128		per_cpu(xen_callfunc_irq, cpu).irq = -1;
129		kfree(per_cpu(xen_callfunc_irq, cpu).name);
130		per_cpu(xen_callfunc_irq, cpu).name = NULL;
131	}
132	if (per_cpu(xen_debug_irq, cpu).irq >= 0) {
133		unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu).irq, NULL);
134		per_cpu(xen_debug_irq, cpu).irq = -1;
135		kfree(per_cpu(xen_debug_irq, cpu).name);
136		per_cpu(xen_debug_irq, cpu).name = NULL;
137	}
138	if (per_cpu(xen_callfuncsingle_irq, cpu).irq >= 0) {
139		unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu).irq,
140				       NULL);
141		per_cpu(xen_callfuncsingle_irq, cpu).irq = -1;
142		kfree(per_cpu(xen_callfuncsingle_irq, cpu).name);
143		per_cpu(xen_callfuncsingle_irq, cpu).name = NULL;
144	}
145	if (xen_hvm_domain())
146		return;
147
148	if (per_cpu(xen_irq_work, cpu).irq >= 0) {
149		unbind_from_irqhandler(per_cpu(xen_irq_work, cpu).irq, NULL);
150		per_cpu(xen_irq_work, cpu).irq = -1;
151		kfree(per_cpu(xen_irq_work, cpu).name);
152		per_cpu(xen_irq_work, cpu).name = NULL;
153	}
154
155	if (per_cpu(xen_pmu_irq, cpu).irq >= 0) {
156		unbind_from_irqhandler(per_cpu(xen_pmu_irq, cpu).irq, NULL);
157		per_cpu(xen_pmu_irq, cpu).irq = -1;
158		kfree(per_cpu(xen_pmu_irq, cpu).name);
159		per_cpu(xen_pmu_irq, cpu).name = NULL;
160	}
161};
162static int xen_smp_intr_init(unsigned int cpu)
163{
164	int rc;
165	char *resched_name, *callfunc_name, *debug_name, *pmu_name;
166
167	resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
168	rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
169				    cpu,
170				    xen_reschedule_interrupt,
171				    IRQF_PERCPU|IRQF_NOBALANCING,
172				    resched_name,
173				    NULL);
174	if (rc < 0)
175		goto fail;
176	per_cpu(xen_resched_irq, cpu).irq = rc;
177	per_cpu(xen_resched_irq, cpu).name = resched_name;
178
179	callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
180	rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
181				    cpu,
182				    xen_call_function_interrupt,
183				    IRQF_PERCPU|IRQF_NOBALANCING,
184				    callfunc_name,
185				    NULL);
186	if (rc < 0)
187		goto fail;
188	per_cpu(xen_callfunc_irq, cpu).irq = rc;
189	per_cpu(xen_callfunc_irq, cpu).name = callfunc_name;
190
191	debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
192	rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt,
193				     IRQF_PERCPU | IRQF_NOBALANCING,
194				     debug_name, NULL);
195	if (rc < 0)
196		goto fail;
197	per_cpu(xen_debug_irq, cpu).irq = rc;
198	per_cpu(xen_debug_irq, cpu).name = debug_name;
199
200	callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
201	rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
202				    cpu,
203				    xen_call_function_single_interrupt,
204				    IRQF_PERCPU|IRQF_NOBALANCING,
205				    callfunc_name,
206				    NULL);
207	if (rc < 0)
208		goto fail;
209	per_cpu(xen_callfuncsingle_irq, cpu).irq = rc;
210	per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name;
211
212	/*
213	 * The IRQ worker on PVHVM goes through the native path and uses the
214	 * IPI mechanism.
215	 */
216	if (xen_hvm_domain())
217		return 0;
218
219	callfunc_name = kasprintf(GFP_KERNEL, "irqwork%d", cpu);
220	rc = bind_ipi_to_irqhandler(XEN_IRQ_WORK_VECTOR,
221				    cpu,
222				    xen_irq_work_interrupt,
223				    IRQF_PERCPU|IRQF_NOBALANCING,
224				    callfunc_name,
225				    NULL);
226	if (rc < 0)
227		goto fail;
228	per_cpu(xen_irq_work, cpu).irq = rc;
229	per_cpu(xen_irq_work, cpu).name = callfunc_name;
230
231	if (is_xen_pmu(cpu)) {
232		pmu_name = kasprintf(GFP_KERNEL, "pmu%d", cpu);
233		rc = bind_virq_to_irqhandler(VIRQ_XENPMU, cpu,
234					     xen_pmu_irq_handler,
235					     IRQF_PERCPU|IRQF_NOBALANCING,
236					     pmu_name, NULL);
237		if (rc < 0)
238			goto fail;
239		per_cpu(xen_pmu_irq, cpu).irq = rc;
240		per_cpu(xen_pmu_irq, cpu).name = pmu_name;
241	}
242
243	return 0;
244
245 fail:
246	xen_smp_intr_free(cpu);
247	return rc;
248}
249
250static void __init xen_fill_possible_map(void)
251{
252	int i, rc;
 
 
 
 
 
253
254	if (xen_initial_domain())
255		return;
256
257	for (i = 0; i < nr_cpu_ids; i++) {
258		rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
259		if (rc >= 0) {
260			num_processors++;
261			set_cpu_possible(i, true);
262		}
263	}
264}
265
266static void __init xen_filter_cpu_maps(void)
267{
268	int i, rc;
269	unsigned int subtract = 0;
270
271	if (!xen_initial_domain())
272		return;
273
274	num_processors = 0;
275	disabled_cpus = 0;
276	for (i = 0; i < nr_cpu_ids; i++) {
277		rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
278		if (rc >= 0) {
279			num_processors++;
280			set_cpu_possible(i, true);
281		} else {
282			set_cpu_possible(i, false);
283			set_cpu_present(i, false);
284			subtract++;
285		}
286	}
287#ifdef CONFIG_HOTPLUG_CPU
288	/* This is akin to using 'nr_cpus' on the Linux command line.
289	 * Which is OK as when we use 'dom0_max_vcpus=X' we can only
290	 * have up to X, while nr_cpu_ids is greater than X. This
291	 * normally is not a problem, except when CPU hotplugging
292	 * is involved and then there might be more than X CPUs
293	 * in the guest - which will not work as there is no
294	 * hypercall to expand the max number of VCPUs an already
295	 * running guest has. So cap it up to X. */
296	if (subtract)
297		nr_cpu_ids = nr_cpu_ids - subtract;
298#endif
299
300}
301
302static void __init xen_smp_prepare_boot_cpu(void)
303{
304	BUG_ON(smp_processor_id() != 0);
305	native_smp_prepare_boot_cpu();
306
307	if (xen_pv_domain()) {
308		if (!xen_feature(XENFEAT_writable_page_tables))
309			/* We've switched to the "real" per-cpu gdt, so make
310			 * sure the old memory can be recycled. */
311			make_lowmem_page_readwrite(xen_initial_gdt);
312
313#ifdef CONFIG_X86_32
314		/*
315		 * Xen starts us with XEN_FLAT_RING1_DS, but linux code
316		 * expects __USER_DS
317		 */
318		loadsegment(ds, __USER_DS);
319		loadsegment(es, __USER_DS);
320#endif
321
322		xen_filter_cpu_maps();
323		xen_setup_vcpu_info_placement();
324	}
325	/*
326	 * The alternative logic (which patches the unlock/lock) runs before
327	 * the smp bootup up code is activated. Hence we need to set this up
328	 * the core kernel is being patched. Otherwise we will have only
329	 * modules patched but not core code.
330	 */
331	xen_init_spinlocks();
332}
333
334static void __init xen_smp_prepare_cpus(unsigned int max_cpus)
335{
336	unsigned cpu;
337	unsigned int i;
338
339	if (skip_ioapic_setup) {
340		char *m = (max_cpus == 0) ?
341			"The nosmp parameter is incompatible with Xen; " \
342			"use Xen dom0_max_vcpus=1 parameter" :
343			"The noapic parameter is incompatible with Xen";
344
345		xen_raw_printk(m);
346		panic(m);
347	}
348	xen_init_lock_cpu(0);
349
350	smp_store_boot_cpu_info();
351	cpu_data(0).x86_max_cores = 1;
352
353	for_each_possible_cpu(i) {
354		zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
355		zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
356		zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL);
357	}
358	set_cpu_sibling_map(0);
359
360	xen_pmu_init(0);
361
362	if (xen_smp_intr_init(0))
363		BUG();
364
365	if (!alloc_cpumask_var(&xen_cpu_initialized_map, GFP_KERNEL))
366		panic("could not allocate xen_cpu_initialized_map\n");
367
368	cpumask_copy(xen_cpu_initialized_map, cpumask_of(0));
369
370	/* Restrict the possible_map according to max_cpus. */
371	while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) {
372		for (cpu = nr_cpu_ids - 1; !cpu_possible(cpu); cpu--)
373			continue;
374		set_cpu_possible(cpu, false);
375	}
376
377	for_each_possible_cpu(cpu)
378		set_cpu_present(cpu, true);
379}
380
381static int
382cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
383{
384	struct vcpu_guest_context *ctxt;
385	struct desc_struct *gdt;
386	unsigned long gdt_mfn;
387
388	/* used to tell cpu_init() that it can proceed with initialization */
389	cpumask_set_cpu(cpu, cpu_callout_mask);
390	if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map))
391		return 0;
392
393	ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
394	if (ctxt == NULL)
395		return -ENOMEM;
396
397	gdt = get_cpu_gdt_table(cpu);
398
399#ifdef CONFIG_X86_32
400	/* Note: PVH is not yet supported on x86_32. */
401	ctxt->user_regs.fs = __KERNEL_PERCPU;
402	ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
403#endif
404	memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));
405
406	if (!xen_feature(XENFEAT_auto_translated_physmap)) {
407		ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
408		ctxt->flags = VGCF_IN_KERNEL;
409		ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
410		ctxt->user_regs.ds = __USER_DS;
411		ctxt->user_regs.es = __USER_DS;
412		ctxt->user_regs.ss = __KERNEL_DS;
413
414		xen_copy_trap_info(ctxt->trap_ctxt);
415
416		ctxt->ldt_ents = 0;
417
418		BUG_ON((unsigned long)gdt & ~PAGE_MASK);
419
420		gdt_mfn = arbitrary_virt_to_mfn(gdt);
421		make_lowmem_page_readonly(gdt);
422		make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));
423
424		ctxt->gdt_frames[0] = gdt_mfn;
425		ctxt->gdt_ents      = GDT_ENTRIES;
426
427		ctxt->kernel_ss = __KERNEL_DS;
428		ctxt->kernel_sp = idle->thread.sp0;
429
430#ifdef CONFIG_X86_32
431		ctxt->event_callback_cs     = __KERNEL_CS;
432		ctxt->failsafe_callback_cs  = __KERNEL_CS;
433#else
434		ctxt->gs_base_kernel = per_cpu_offset(cpu);
435#endif
436		ctxt->event_callback_eip    =
437					(unsigned long)xen_hypervisor_callback;
438		ctxt->failsafe_callback_eip =
439					(unsigned long)xen_failsafe_callback;
440		ctxt->user_regs.cs = __KERNEL_CS;
441		per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);
442	}
443#ifdef CONFIG_XEN_PVH
444	else {
445		/*
446		 * The vcpu comes on kernel page tables which have the NX pte
447		 * bit set. This means before DS/SS is touched, NX in
448		 * EFER must be set. Hence the following assembly glue code.
449		 */
450		ctxt->user_regs.eip = (unsigned long)xen_pvh_early_cpu_init;
451		ctxt->user_regs.rdi = cpu;
452		ctxt->user_regs.rsi = true;  /* entry == true */
453	}
454#endif
455	ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
456	ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_gfn(swapper_pg_dir));
457	if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
458		BUG();
459
460	kfree(ctxt);
461	return 0;
462}
463
464static int xen_cpu_up(unsigned int cpu, struct task_struct *idle)
465{
466	int rc;
467
468	common_cpu_up(cpu, idle);
469
470	xen_setup_runstate_info(cpu);
471	xen_setup_timer(cpu);
472	xen_init_lock_cpu(cpu);
473
474	/*
475	 * PV VCPUs are always successfully taken down (see 'while' loop
476	 * in xen_cpu_die()), so -EBUSY is an error.
477	 */
478	rc = cpu_check_up_prepare(cpu);
479	if (rc)
480		return rc;
481
482	/* make sure interrupts start blocked */
483	per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1;
484
485	rc = cpu_initialize_context(cpu, idle);
486	if (rc)
487		return rc;
488
489	xen_pmu_init(cpu);
490
491	rc = xen_smp_intr_init(cpu);
492	if (rc)
493		return rc;
494
495	rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL);
496	BUG_ON(rc);
497
498	while (cpu_report_state(cpu) != CPU_ONLINE)
499		HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
500
501	return 0;
502}
503
504static void xen_smp_cpus_done(unsigned int max_cpus)
505{
506}
507
508#ifdef CONFIG_HOTPLUG_CPU
509static int xen_cpu_disable(void)
510{
511	unsigned int cpu = smp_processor_id();
512	if (cpu == 0)
513		return -EBUSY;
514
515	cpu_disable_common();
516
517	load_cr3(swapper_pg_dir);
518	return 0;
519}
520
521static void xen_cpu_die(unsigned int cpu)
522{
523	while (xen_pv_domain() && HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL)) {
524		__set_current_state(TASK_UNINTERRUPTIBLE);
525		schedule_timeout(HZ/10);
526	}
527
528	if (common_cpu_die(cpu) == 0) {
529		xen_smp_intr_free(cpu);
530		xen_uninit_lock_cpu(cpu);
531		xen_teardown_timer(cpu);
532		xen_pmu_finish(cpu);
533	}
534}
535
536static void xen_play_dead(void) /* used only with HOTPLUG_CPU */
537{
538	play_dead_common();
539	HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
540	cpu_bringup();
541	/*
542	 * commit 4b0c0f294 (tick: Cleanup NOHZ per cpu data on cpu down)
543	 * clears certain data that the cpu_idle loop (which called us
544	 * and that we return from) expects. The only way to get that
545	 * data back is to call:
546	 */
547	tick_nohz_idle_enter();
548
549	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
550}
551
552#else /* !CONFIG_HOTPLUG_CPU */
553static int xen_cpu_disable(void)
554{
555	return -ENOSYS;
556}
557
558static void xen_cpu_die(unsigned int cpu)
559{
560	BUG();
561}
562
563static void xen_play_dead(void)
564{
565	BUG();
566}
567
568#endif
569static void stop_self(void *v)
570{
571	int cpu = smp_processor_id();
572
573	/* make sure we're not pinning something down */
574	load_cr3(swapper_pg_dir);
575	/* should set up a minimal gdt */
576
577	set_cpu_online(cpu, false);
578
579	HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL);
580	BUG();
581}
582
583static void xen_stop_other_cpus(int wait)
584{
585	smp_call_function(stop_self, NULL, wait);
586}
587
588static void xen_smp_send_reschedule(int cpu)
589{
590	xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
591}
592
593static void __xen_send_IPI_mask(const struct cpumask *mask,
594			      int vector)
595{
596	unsigned cpu;
597
598	for_each_cpu_and(cpu, mask, cpu_online_mask)
599		xen_send_IPI_one(cpu, vector);
600}
601
602static void xen_smp_send_call_function_ipi(const struct cpumask *mask)
603{
604	int cpu;
605
606	__xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
607
608	/* Make sure other vcpus get a chance to run if they need to. */
609	for_each_cpu(cpu, mask) {
610		if (xen_vcpu_stolen(cpu)) {
611			HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
612			break;
613		}
614	}
615}
616
617static void xen_smp_send_call_function_single_ipi(int cpu)
618{
619	__xen_send_IPI_mask(cpumask_of(cpu),
620			  XEN_CALL_FUNCTION_SINGLE_VECTOR);
621}
622
623static inline int xen_map_vector(int vector)
624{
625	int xen_vector;
626
627	switch (vector) {
628	case RESCHEDULE_VECTOR:
629		xen_vector = XEN_RESCHEDULE_VECTOR;
630		break;
631	case CALL_FUNCTION_VECTOR:
632		xen_vector = XEN_CALL_FUNCTION_VECTOR;
633		break;
634	case CALL_FUNCTION_SINGLE_VECTOR:
635		xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
636		break;
637	case IRQ_WORK_VECTOR:
638		xen_vector = XEN_IRQ_WORK_VECTOR;
639		break;
640#ifdef CONFIG_X86_64
641	case NMI_VECTOR:
642	case APIC_DM_NMI: /* Some use that instead of NMI_VECTOR */
643		xen_vector = XEN_NMI_VECTOR;
644		break;
645#endif
646	default:
647		xen_vector = -1;
648		printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
649			vector);
650	}
651
652	return xen_vector;
653}
654
655void xen_send_IPI_mask(const struct cpumask *mask,
656			      int vector)
657{
658	int xen_vector = xen_map_vector(vector);
659
660	if (xen_vector >= 0)
661		__xen_send_IPI_mask(mask, xen_vector);
662}
663
664void xen_send_IPI_all(int vector)
665{
666	int xen_vector = xen_map_vector(vector);
667
668	if (xen_vector >= 0)
669		__xen_send_IPI_mask(cpu_online_mask, xen_vector);
670}
671
672void xen_send_IPI_self(int vector)
673{
674	int xen_vector = xen_map_vector(vector);
675
676	if (xen_vector >= 0)
677		xen_send_IPI_one(smp_processor_id(), xen_vector);
678}
679
680void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
681				int vector)
682{
683	unsigned cpu;
684	unsigned int this_cpu = smp_processor_id();
685	int xen_vector = xen_map_vector(vector);
686
687	if (!(num_online_cpus() > 1) || (xen_vector < 0))
688		return;
689
690	for_each_cpu_and(cpu, mask, cpu_online_mask) {
691		if (this_cpu == cpu)
692			continue;
693
694		xen_send_IPI_one(cpu, xen_vector);
695	}
696}
697
698void xen_send_IPI_allbutself(int vector)
699{
700	xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
701}
702
703static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
704{
705	irq_enter();
706	generic_smp_call_function_interrupt();
707	inc_irq_stat(irq_call_count);
708	irq_exit();
709
710	return IRQ_HANDLED;
711}
712
713static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
714{
715	irq_enter();
716	generic_smp_call_function_single_interrupt();
717	inc_irq_stat(irq_call_count);
718	irq_exit();
719
720	return IRQ_HANDLED;
721}
722
723static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id)
724{
725	irq_enter();
726	irq_work_run();
727	inc_irq_stat(apic_irq_work_irqs);
728	irq_exit();
729
730	return IRQ_HANDLED;
731}
732
733static const struct smp_ops xen_smp_ops __initconst = {
734	.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
735	.smp_prepare_cpus = xen_smp_prepare_cpus,
736	.smp_cpus_done = xen_smp_cpus_done,
737
738	.cpu_up = xen_cpu_up,
739	.cpu_die = xen_cpu_die,
740	.cpu_disable = xen_cpu_disable,
741	.play_dead = xen_play_dead,
742
743	.stop_other_cpus = xen_stop_other_cpus,
744	.smp_send_reschedule = xen_smp_send_reschedule,
745
746	.send_call_func_ipi = xen_smp_send_call_function_ipi,
747	.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi,
748};
749
750void __init xen_smp_init(void)
751{
752	smp_ops = xen_smp_ops;
753	xen_fill_possible_map();
754}
755
756static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
757{
758	native_smp_prepare_cpus(max_cpus);
759	WARN_ON(xen_smp_intr_init(0));
760
761	xen_init_lock_cpu(0);
762}
763
764static int xen_hvm_cpu_up(unsigned int cpu, struct task_struct *tidle)
765{
766	int rc;
767
768	/*
769	 * This can happen if CPU was offlined earlier and
770	 * offlining timed out in common_cpu_die().
771	 */
772	if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) {
773		xen_smp_intr_free(cpu);
774		xen_uninit_lock_cpu(cpu);
775	}
776
777	/*
778	 * xen_smp_intr_init() needs to run before native_cpu_up()
779	 * so that IPI vectors are set up on the booting CPU before
780	 * it is marked online in native_cpu_up().
781	*/
782	rc = xen_smp_intr_init(cpu);
783	WARN_ON(rc);
784	if (!rc)
785		rc =  native_cpu_up(cpu, tidle);
786
787	/*
788	 * We must initialize the slowpath CPU kicker _after_ the native
789	 * path has executed. If we initialized it before none of the
790	 * unlocker IPI kicks would reach the booting CPU as the booting
791	 * CPU had not set itself 'online' in cpu_online_mask. That mask
792	 * is checked when IPIs are sent (on HVM at least).
793	 */
794	xen_init_lock_cpu(cpu);
795	return rc;
796}
797
798void __init xen_hvm_smp_init(void)
799{
800	if (!xen_have_vector_callback)
801		return;
802	smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
803	smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
804	smp_ops.cpu_up = xen_hvm_cpu_up;
805	smp_ops.cpu_die = xen_cpu_die;
806	smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi;
807	smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi;
808	smp_ops.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu;
809}